This invention relates, in general, to the construction of space heaters and, in particular, to a new and useful engine-independent space heater, particularly for automobiles which includes a mixture preparation device.
The invention relates to a device for mixture preparation in engine-independent heaters, having a combustion chamber and an antechamber thereof into which an ignition device protrudes to ignite the prepared explosive mixture and which antechamber cooperates with a combustion chamber.
In engine-independent heaters, good mixture preparation for ignition and combustion of the fuel-air mixture is especially important because naturally the efficiency of the heater depends on it. What is required of such heaters is in particular that they must be operational in a wide temperature range and be able to be operated with a minimum of current consumption, as the current supply is from the vehicle's own battery.
Another requirement is that the relatively small fuel quantities are supplied reliably and are prepared for operation with an adequate proportion of combustion or start-up air.
Engine-independent heaters are known where the fuel supply and preparation is effected through a fuel nozzle. These nozzles are high-pressure atomizer nozzles. Their operation shows a relatively high current consumption, because the fuel must first be brought to the high pressure required for the atomization by the fuel nozzle. For small heaters another difficulty is that the required small nozzles--for quantities in the range of below about 2.5 l/hr, in particular 0.3 l/h--are not available.
Further heaters are known where the mixture preparation occurs through a so-called rotary distributor, a disk on which the fuel is applied during its rotation at high speed. Since the fuel preparation and ignition occurs in the hot part of the heater, this means that movable parts, namely the rotary distributor, are exposed to high temperatures.
Also in the operation of heaters where the ignition of th fuel-air mixture occurs through an incandescent coil, the disadvantage of high current consumption occurs. Another factor is a dependence of such arrangements on voltage differences, leading to higher trouble proneness. An object of the invention is to provide a device for mixture preparation in engine-independent heaters which can take the place of the high-pressure atomizer nozzle or rotary distributor serving for mixture formation and which does not have the disadvantages thereof and in particular has a low current consumption or can replace an arrangement with ignition by an incandescent coil.